Ring bending mechanism



Dec. 20, 1938.. G, C, MINISTER RING BENDING MECHANISM ,4

Filed June 7, 1957 Patented Dec. 20, 1938 PATENT OFFICE RING BENDING MECHANISM George O. Minister, Columbus, Ohio, assignor to The Josten Manufacturing Co.,

Owatonna,

Minn., a corporation of Minnesota. Application June 7, 1937, Serial No. 146,757

1 Claim.

VThe invention relates to iinger ring bending mechanisms and more particularly to a mechanism of this type adapted to shape a generally straight elongated ring blank intoannular form.

One object of the present invention is to provide an impro-ved mechanism of the type set forth which is simple and rugged in construction and which is easy to operate.

A more specic object of the invention is to provide such a mechanism which is especially adapted to bend ring blanks for signet rings into annular shape with a true circular inner surface despite irregularities in the thickness and surface contour of the ring.

Further objects and advantages of the invention will become apparent as the following description proceeds and the features of novelty which characterize the invention are pointed out with particularity in the claim annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had tothe accompanying drawing in which Figure 1 is a perspective View of a ring bending mechanism embodying the invention.

Fig. 2 is a longitudinal sectional view of the mechanism shown in Fig. 1.

Figs. 3 and 4 are respectively perspective and longitudinal sectional views of a ring blank adapted to be operated upon by the mechanism shown in Figs. 1 and 2.

Figs. 5, 6 and 7 are fragmentary horizontal plan views of a portion of the bending mechanism shown in Figs. 1 and 2 illustrating successive steps in the operations performed on a ring blank such as that shown in Figs. 3 and 4.

For purposes of illustration, the invention has been shown herein as embodied in a mechanism particularly adapted for bending finger ring blanks of the type disclosed in my Patent No. 2,035,562, issued March 31, 1936, but it will be understood that the present invention is also applicable to the bending of other types of ring blanks. The bending mechanism includes in general a cylindrical forming member or anvil I0 about which the ring blank is bent, a relatively movable clamping member II adapted to clamp the blank in position against the cylinder I0, and a smoothing member I2 operable to bend the laterally extending portions of the clamped blank about the cylinder, all of these parts being carried by a base I3.

In the particular construction illustrated, the cylindrical forming member I0 is shown as carried by an axially extending pin I4 inserted in a bore I5 in the base I3 and detachably held in position therein by a set screw I6. The forming vmember may thus be readily detached from the I8 is eiected by a cam 20 peripherally engageable with the butt of the plunger I8 and pivotally mounted on an eccentrically located pin. 2I threaded in the base I3. Rotation of the cam 20 is had by a manual operating handle 22. A tension spring 23 secured at its opposite ends to pins 24 and 25, i'lXed respectively on the plunger I8 and pivot 2I, serves to maintain the plunger in engagement with the cam so that the plunger is projected and retracted in accordance with the rotation of the actuating cam.

The smoothing member I2 has been illustrated in the form of a roller mounted for swinging movement about the axis of the cylinder I0 as Well as for bodily movement toward and away from the same. Thus, the roller I2 is rotatably mounted on a pin 26 journaled in the bifurcated forward end of a supporting member 2l slidably mounted for longitudinal movement on a swinging arm 28 'by screws 29 passing through elongated guide slots 30. The arm 28 is detachably mounted on an axial boss 3| on the upper end of the forming cylinder I0 for swinging movement about the same.

Axial movement of the supporting member 2l and its attached smoothing roller I2 is preferably effected by a manually operated screw mechanism in order that the operator may readily determine the pressure required in the manipulation of the mechanism. In the device illustrated, the roller I2 is shifted bodily toward and away from the axis of the forming cylinder I0 by rotation of a screw 32 having a manual operating handle 33 and threaded in the swinging arm 28, the inner end of the screw being splined to the supporting member 2l as indicated at 33 (Fig. 2).

A signet ring blank 34 of the type referred to above has been shown in Figs. 3 and 4. This blank includes an outer member 35 having a recessed lower side and an inner lining member 38. The central portion 31 of the blank is recessed inwardly as indicated at 38.

As the first step in fashioning the blank 34 intoV the desired annular shape, the outer surface of the depressed or recessed portion 38 is bent flat. To this end, the blank is positioned between the forming cylinder l and clamping plate Il (Fig. whereupon the plunger I8 is moved axially toward the forming cylinder, thus attening the recessed central portion of the blank and causing the laterally extending portions 39 of the blank to be bent at an angle with re' speet to the center portion (Fig. 6'). This ,displacement of the lateral ends of the blank, together with the tapered contour of the nose of the housing i5, permits the smoothing roller l2 to be positioned, as shown in Fig. 6, against one of the shanks of the ring blank. The operator moves the smoothing roller l2 into ilrm engagement with the blank by rotatingv the screw 32 and subsequently swings the arm 28 and its attached roller I2 about the axis of the forming cylinder lil in the direction of the arrow 40 (Fig. 6) thus bending the laterally extending portion 39 of the ring blank about the cylinder into the conguration shown in Fig. 7. VIn the course of this bending operation theV operator moves the roller I2 toward the axis of the formingV member I0 as the thickness of the blank decreases so that a uniform bending pressure is applied to the ring blank. Subsequently, the second laterally extending portion of the blank is bent about the forming cylinder I0 in a like manner. The blank may then be removed from the forming cylinder and the abutting ends soldered or otherwise secured together.

Although a particular embodiment of the invention has been shown and described in some detail for purposes of illustration, there is no intention to thereby limit the invention to such embodiment but, on the other hand, the appended claim is intended to cover all modifications within thespirit and scope of the invention. Y

I claim as my invention:

In a mechanism for forming finger rings from elongated generally straight blanks, the combination of, a base, a forming cylinder on said base of a diameter equal to the desired interior diameter for the nished ring, a clamping member mounted for axial sliding movement on said base toward and away from said cylinder to clamp the central portion of the blank therebetween, means including a peripheral cam pivoted on said base adjacent the outer end of said clamping member for moving the same into and outI of clamping position with respect to said cylinderin response to oscillation of said cam, said last named means including means for urging said outer end of said axial sliding clamping member into abutment with the periphery of said oscillatable cam, means including a roller arranged for swinging movement about the axis of said cylinder for progressively pressing the laterally extending portions of the clamped blank against the cylinder in ring shape, and means including a screw member for moving said roller toward and away from said axis.

GEORGE C. MINISTER. 

